import java.util.Scanner;

public class Test {
    public static int fib(int n){
        if (n <= 2){
            return n;
        }
            return fib(n-2)+fib(n-1);
    }
    public static void main(String[] args) {
//        1 1 2 3 5 8 ....
        while (true){
            System.out.println("请输入：");
            Scanner scanner = new Scanner(System.in);
            int n = scanner.nextInt();
            int ret = fib(n);
            System.out.println(ret);
        }
    }
}
